1. Field of the Invention
The present invention relates to a turret head unit adapted to carry out drilling or like operations and having a plurality of angularly disposed tool receiving spindles mounted therein.
2. Description of the Prior Art
Conventionally, a turret head unit of this kind requires indexing of the turret head and clamping thereof, and has been usually provided with a hydraulic mechanism serving as means for performing these operations.
Such a conventional hydraulic mechanism, however, has been complicated in construction, with the result that the whole apparatus tends to become massive. Further, since the hydraulic mechanism for poor responsiveness, it has not satisfied the demands for reduction of machining time and for high speed operation of machine tools.